At the SUNY Cobleskill farm alfalfa weevil was at threshold on
alfalfa re-growth. There were many larvae, and many were still small,
ranging from 1st to 3rd instar. Remember,
the action threshold for alfalfa weevil on 2nd cutting
is 50 percent tip feeding with small larvae present. There was also
potato leafhopper present at low numbers in the fields. In
a corn seed planting depth research trial at SUNY Cobleskill being
conducted by Kevin Ganoe (Central NY Dairy and Field Crop Team),
all of the corn seed planted at 1 inch or less was picked out and
consumed by crows. The deepest planted plots had no bird damage.

Birds removed all shallow planted corn seed

Tom Kilcer (Capital District) reports a few corn fields over
threshold for black cutworm. Patricia Westenbroek (
SullivanCounty) reports that black cutworm has
been an issue in a few field. For more information on black cutworm
view the article below.

Western NYS and
Finger Lakes Region

Mike Stanyard (Northwest NY Dairy and Field Crop Team) reports
heavy infestations of common armyworm in winter wheat. Infestation
levels ranged form 4 to 15 larvae per square foot. Remember that
armyworm can go undetected because most of the damage they do is
in the last larval instar. Keep a close eye on your small
grains, corn and grass fields for armyworm. Mike Stanyard also reports
some corn fields were over threshold for black cutworm. He is also
starting to see cereal leaf beetle in some oat fields. Dean Sprague
(Allegany, Cattaraugus, and
ChautauquaCounties) reports that some wheat and
oat fields had armyworm damage. Mike Dennis (
SenecaCounty) reports finding potato leafhoppers.
Keith Waldron reports fireflies observed in
Ontario county. These insects are typically seen
about the same time of year that corn rootworm eggs begin to hatch.

The past week saw very hot weather with temperatures region wide
running well above normal. Almost the entire state ended up 9 to
15 degrees warmer than average. Precipitation was hard to come by
in Central and
Western New York, where generally less than half an inch
fell. Rain was more abundant further east, where 1 to 3 inches fell.

Base 50 Growing Degree Days accumulated 150-200 across most of
the state, with the mountain areas receiving 100-150. For the season,
this puts most areas between 300 and 500, the exception again being
the
Adirondacks and Catskills where there have been 200-400.
Compared to last year, this puts most areas within 75 growing degree
days on either side of last year.
Southeastern New York is the exception, which is 75 to 150
Growing Degree Days behind last year. The entire state is now running
about 3 to 7 calendar days above normal.

Forecast:

Another pattern shift is in store for the Northeast over the
course of the next week as we shift from above average temperatures
Friday and Saturday, to below average temperatures by next week.
With a high pressure centered off the
SoutheastCoast tomorrow [Friday], south-westerly
winds will bring hot, humid weather back on Friday, when highs across
the region could approach 90 with a couple pop-up thunderstorms.
Lows Saturday morning will generally be in the mid to upper 60’s.
A cold front will move from west to east with a better chance for
thunderstorms on Saturday. With highs in the mid 80’s and the humidity
up, some of those storms could again be severe. Drier weather will
come in Sunday, with lows will be in the upper 50’s to near 60 and
highs will generally be near 80. Another front will come through
on Monday, bringing another chance for rain. Lows will be near 60
and highs in the mid to upper 70’s. The area of low pressure associated
with this front will then park itself over southeastern
Canada. This will keep showers possible
on Tuesday, with a lesser chance on Wednesday. Highs will only be
in the low 70’s Tuesday and many places will not get above 70 on
Wednesday. Low temperatures won’t see as drastic a cool down, with
lows in the low to mid 50’s both days. Precipitation amounts look
to generally be near or slightly below 1”, with the higher amounts
typically in the west. This cool pattern looks to continue into
the 8-14 day period, with temperatures below to well below normal
with average precipitation.

A few fields in
Eastern NYS were reported hit by infestations of black cutworm
this last week.

The cutworm adult moths ride weather fronts that carry them from
the south to the Northeast. Weedy grasses and winter annual
broadleaves (especially chickweed) are favorite targets. If cutworm
moths lay eggs in the field and the field is treated with an herbicide,
hatching cutworm larvae bail off the dying weeds and look for greener
food sources such as emerging corn seedlings. Cutworms can be an
annual problem in some fields; particularly those with a history
of poor weed control or with low wet areas in the field. Field margins,
especially those next to ditch banks, grassy lanes, and hay fields
are potential sites for infestation. Doing an early season plant
population count is a good way to check corn fields for cutworm
damage and other corn emergence problems.

Black cutworm larvae vary in color from light gray to black with
a pale brown to black head. Larvae have a greasy, shiny appearance
with coarse granules present over their body. During the day larvae
burrow into the soil next to the corn plant. These larvae curl into
a C-shape when disturbed. Symptoms of damage are leaf feeding, irregular
holes in stems, notched and cut or missing plants. No-till fields
and those with a lot of grass weeds are at particular risk to black
cutworm. Monitor fields to find cutworm larvae when they are less
than 1/2 inch long. If there are sufficient numbers and if 5% or
more plants have been cut, an insecticide could be justified. Treat
only the affected area and a 20 to 40-foot border around the infestation.
Rarely does a whole field need to be treated for cutworm. Larger
cutworm larvae, greater than 1/2 inch long, are much more difficult
to control. If the majority of cutworm larvae are 1/2 inch long
or larger their damage is already done. These large larvae are also
more tolerant of insecticides, reducing the effectiveness and economic
viability of this option. Check out our on-line publication,
Black Cutworm in Field Corn Management Guide.

Soybeans seem to have sprung out of the ground overnight during
this week’s heat wave, so it will soon be time to assess soybean
stands. The to-do list includes estimating plant populations and
investigating the cause of missing plants in the rows. These activities
will be conducted at soybean TAg Team meetings occurring over the
next couple of weeks.

The following table summarizes a method for estimating plant
populations. Count the number of plants in the given length of row
based on the row spacing, and then add 3 zeros. (For example, if
165 plants are counted, your estimated plant population is 165,000).
Repeat this for the number of rows in your planter or drill, and
repeat in 2 more areas of the field.

If the row width is:(inches)

Then measure this length of row:

7

74 feet, 8 inches

15

34 feet, 10 inches

20

26 feet, 2 inches

30

17 feet, 5 inches

32

16 feet, 4 inches

36

14 feet, 6 inches

When skips are seen in the rows, it is time to do some digging.
Are seeds planted too deep such that plants are still emerging?
Was the planter or drill acting up? Are damaged seeds or seedlings
seen? If seeds are mushy or rotten, a seed or seedling blight might
be the problem.
See Ken’s article for detailed descriptions of disease problems
in soybean seedlings in the May 29th issue.

If seeds, stems, or roots show signs of feeding injury, the usual
suspects are seed corn maggot, wireworm, or white grub. Risk from
seed corn maggot is greatest if there is high organic matter on
the soil surface, from crop residue or manure, for example. Wireworm
and grub threats are usually greatest following a grass or pasture
sod.

Stand assessment information gathered this year will help guide
decisions about management that may be warranted in future years.

Scouting alfalfa fields is the key to early detection of potato
leafhopper infestations. Use a 15-inch diameter sweep net to determine
the potential risk a potato leafhopper infestation may pose to your
alfalfa. Scouting for potato leafhopper starts after the first cutting
of alfalfa (about the first part of June) till the first fall frost.
You will want to use a potato leafhopper sequential sampling plan
to determine if an infestation requires management or not. The first
thing to do is determine the height of your alfalfa. Smaller plants
are more vulnerable to potato leafhopper; thus there are different
action thresholds for different heights of alfalfa. The second thing
you will need to know is how to sample for potato leafhopper. A
sample consists of a set of 10 sweeps of the net. A sweep is one
pass in front of you as you walk through the alfalfa. The return
swing is counted as another sweep. Sequential sampling reduces the
time spent in each field and tells you whether to treat (management
action) or not treat (no management action). Sequential sampling
is particularly helpful in minimizing time required to make a management
decision in situations where PLH populations are very high or very
low. Use the following chart to determine potato leafhopper infestation
levels.

N= No management needed at this time

T= Management needed as soon as possible

Write down the number of potato leafhoppers for each sample taken
on the card. Add each sample to the next, keeping a running total
of potato leafhoppers. You will need to take at least 3 samples
using the sequential sampling method. On the sequential sampling
card “N” is defined as no treatment (no management) needed at this
time and “T” is defined as treatment (management) needed within
in a week. If the sample is smaller than the “N” number stop and
scout 7 days later. If the number of leafhoppers is larger than
the “T” number then management action needs to be taken within a
week. If the number of potato leafhoppers fall between “N” and “T”
then continue and take the next sample till a decision can be determined.
A guide with a printable version of the sequential sampling chart
can be found in our online publication,
Potato Leafhopper on Alfalfa Management Guide.

Sentinel plots in
New YorkState are currently being established in the following
counties: Cayuga, Chautauqua, Chemung,
Columbia,
Cortland, Jefferson, Lewis, Livingston,
Madison, Niagara,
Oneida,
Ontario, Schoharie, Seneca, Steuben and
Wayne. We will continue to provide disease updates
on these plots as the growing season progresses.

Since the beginning of 2008, soybean rust has been reported on
kudzu in one county in
Alabama; ten counties in
Florida (two of these counties had reports on coral bean
and snap bean); three counties in
Louisiana; one county in
Mississippi, and three counties in
Texas. Reported infected kudzu sites in many
counties have been destroyed. Rust was also reported in three states
(5 municipalities) in
Mexico on yam bean and soybean. These
too have been destroyed or are no longer active, except for the
recent find in
Chiapas. Soybean sentinel plots have been established
throughout the
GulfCoast region, and in many parts of the
lower Midwest.(Updated
June 10, 2008 )

If you are unable to reach a Poison Control Center or obtain the
information your doctor needs, the office of the NYS Pesticide Coordinator
at Cornell University,
607-255-1866, may be able to assist
you in obtaining such information.

NYS IPM on:

These pages are maintained by the New York State IPM Program, part of Cornell Cooperative Extension. All material is protected by Section 107 of the 1976 copyright law. Copyright is held by Cornell University and the New York State IPM Program.